If you want to use your old extensions for now, the best version option is to use Firefox ESR which is currently based on Firefox 52. https://www.mozilla.org/en-US/firefox/organizations/https://support.mozilla.org/en-US/kb/sw ... elease-esrIf you use Firefox ESR you will have to decline an update to ESR version 60 in May 2018 and stay on the 52 ESR track. Then, in August you will have to disable updates or try some other method of dealing with your issues. If that is the path you take come back here around then and ask for information about making backups and how to disable updates, because clicking the box to disable updates is often not enough.